Shan is a highly respected cop with a long history of success in dangerous cases, however, his past soon comes back to haunt him when his former protégé seeks revenge against all those who have wronged him.
Cheung Sung-bong is an officer of the Regional Crime Unit who worked in the front line for many years. His protege, Yau Kong-ngo, respects and looks up to him. However, fate conspires to pit them against each other.